Telephone signaling system.



C(L. GOODRUM.

TELEPHONE SIGNALING SYSTEM. APPLICATION FILED NOV. 7, 1914 1,200,829.Patented 'Oct. 10,1916.

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'M (/mr/es L. 6004/11/71.

I v by W UNITED STATES PATENT OFFICE.

' CHARLES L. GOOIJRUM, OF NEW YORK, N. Y., ASSIGNOR, BY MESNEASSIGNMENTS, TO

WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

; TELEPHONE SIGNALING SYSTEM.

Patented Oct. 10, 1916.

Application filed November 7, 1914. Serial No. 870,806.

To all whom it v m'zg concern:

Be it known that I, CHARLES L. Got oRUM,

' acitizen of the United States,'residing at tion of ringing current tothe called.sub scribers line by means of a switch or key which can bereadily controlled by thecall ing subscriber in the transmission of coderinging impulses. I

' A'further object resides in means to prevent the application ofringing current to v the called subscribers line when the calling.subscriber hangs up his receiver. I With the above object in View, theappllcation of ringing current to the called partys line is under thecontrol of a slowacting ringing relay, the circuit of which iscontrolled by a second slow-acting relay which in turn is controlled bya slow-acting release relay, whose circuit-in turn is under control of aline relay. The circuit of the line relay is controlled by aninterrupteractuated by the calling party. The calling party may,therefore, by operating his interrupter, cause the line relay to vibrateand thereby apply-ringing current-to the called partys line. g

The several features of the invention may be more readily understood byreference to the accompanying drawing which is a dia gram of so much ofa two-wire automatic telephone system as is deemed necessary to anunderstandin of the invention.

The calling su scribers station A and the called subscribers station Bmay be connected to each other in the usualwell-known manner, suchconnectionbeing under the control of the dial 1 at the station of thecalling subscriber. By lifting his receiver and actuating thedial, thecalled subscriber controls the operation of the'finder 2 and theconnector 3, thereby connecting the two limbs 4 and 5 of the callingsubscriber s line with the limbs 6 and 7- of the called subscribersline. The applicationof ringing current tothe called'line is dependentupon the vibration of a line relay 8-,,the circuit of which may betraced as follows: from the grounded battery 9, through one winding 10of the line relay 8, the limb 5 of th e telephone line, telephone book11, the interrupter dial 1, the other limb 4 of the telephone line,winding 12 of the relay 8, to ground. After the calling party hasoperatedthe dial to select the line wanted, he may give it another turn,thus sending a ser es of impulses which causes the relay 8'to vibrateand thereby to cause ringing current to be applied to the line of thecalled party in the manner to be hereinafter described.

The impulse transmitter inay be satisfactorily used for ringing purposeswhen the oflice contains no party lines on which code ringmg isessential. However, when code ringing is desirable, the use of theimpulse transmitter is unsatisfactory, whereas a key of the push buttontype can be used to the very best advantage. A key of this type makes itpossible for the subscriber to properly cons trol the longand shortrings ordinarily usedin code ringing. 1

.The relay 8 has a front contact 13 an'd a back contact 14. hen saidrelay is energized, thereby closing its front contact 13, a circuit isclosed for a slow-acting relay 15 as follows: from ground, throughcontact 13, relay 15, to one pole of the grounded battery 9. This causesthe relay 15 to close its contact 16. Relay 15 being ofthe slow releasetype, maintains its contact 16 closed during the time that the linerelay 8 is vibrating. The contact 16 is in the circuit of a secondslow-acting relay 17, the circuit of which ,may be traced as follows:from grounded battery 9, through relay 17,-contact 16, contact 14,closed in the released position of the relay 8, to ground. Relay 17being likewise of the slow release type, maintains its contact 18 closedduring the time the 1 line relay 8 is vibrating. The contact 18 is inthe circuit of a slow-acting ringing relay 19, the circuit of which maybe traced as follows: from the grounded battery 9, through relay 19,contact 18, contact 13, closed in the actuated position of the relay .8,to ground. The relay 19 controls the application of ringing current tothe called line, the circuit therefor being traced as follows: from thegenerator 20, through contact 21 of the ringing relay 19, one limb 6 ofthe called partys line, the bell 22, the other limb 7 of the calledpartys telephone .line,

-. .Since the relay 17 is of theslow releaserype,

' during thevvibration of the, line relay 8.

contact 23 of the ringingrelay 19 to ground.

its contact 18 remains closedduring the v1-v bration of the line relay8, and since. the ringing relay 19 is of the slow release type. itscontacts 21 and 23 likewise remain closed Therefore, when thesubscriber, by meansof an interrupter, sends a series of impulsesoverthe hue 4'--5, he thereby causes ringing current to be impressed uponthe line 67.

[As hereinbefore stated, the subscribers dial' 1 maybe used as aninterrupter for causing the vibration of. the line relay 8. However, incertain cases' it is preferable to employ another'an d independentinterrupter .for thispurpose. In the preferred form of thisinvention,therefore, an electromagneti' cally actuated interrupter is provided,such interrupter comprising the slow-acting elec- .ti-Omagnet 24 and itscontact 25 which are in serie's with one-limbof the callingsubiscriberistelephone line. -This electromag- 1 neticallyactuatedvinterrupter is normally 25 adapted to be manually operated by thecalling subscriber, as, for example, by the actuation of-apush-button'27. It thus appears that the calling subscriberby pressingupon the button 27removes the short-circuit from the electromagneticallyactuated interrupter, and the circuit is, during such oper:

short-circuited by a switch 26 which is p ation of the switch 26, openedand closed at .contact 25, thereby applying intermittent 3 currentto'the relay 8,'an d causing the applicationof ringing current to theline of 1 the called party in the manner hereinbefore" described.-Itwi1l be-noted that so long asl the button 27 is actuated, ringingcurrent is applied to the called line. The electromagnetically actuatedinterrupter, ,therefore,,

provides a convenient means for code ring ing. e v v g This inventionprovides a simple arrangement of circuits and apparatus for placing theringing of thef'called subscriber under the direct'control of thecallingsubscriber.

' Itwill be noted that the circuit arrangements are such that-when thecalling subscriber is connected to the line it requires a it make andbreak 'of the calling line circuit before ringing current is applied tothe called subscribers line. Thus when the calling subscriber isconnected for service and line relay 8 is energized, the slow-actingrelay-15-is also energized. An interruption of the line circuit causesthe deenergization of the line relay 8 whereas the slow-acting I relay15 will remain energized and the circuit completed by the armature ofthe deenergized line relay and the armature of the energized slow-actingrelay 15 will ener gize and operate the slow-acting relay 17. Asubsequent closure of the line circuit will then reenergize the linerelay 8end the relays a circuit closed in the actuated said secondslow-acting relay.

15 and 17 being slow-acting, will likewise be energized and a circuitwill now be completed through the slow-acting ringing relay 19 by way ofthe armaturev of the slowacting relay 17 and the front contact andarmature of the line relay 8.

current can be applied to, it called subscribers line. This isof-considerable advantage in preventing the application of'ringingcurrent to the calling subscribers line when The foregoing descriptionWill makedt evident thata make and breakof the can w cuit' is absolutelyessential before ringing the subscriber has the receiver'ofi the-hook.

Thus, in case it were possibleto energize the ringing relay by simplybreaking the line circuit ofthe; calling subscriber, then if f thecalling subscriber were tohang up his receiver before the calledsubscriber, the j I latter would receive the rin'ging current in hlSreceiver, due to the energizatlon of the advantage, and the secondslow-acting relay 17 wasincluded this circuit to overcome this operatingsystems. p p What is claimed is:

' 1.- In a signaling system, the combination of a calling subscriber sline, a line relay controllable over said line, an impulse sendingdevice operated by. the calling subscriber detect existingin previousringing relay. This would be a serious 'dis for controlling said relay,a slow-acting re 1 lay under the control of said line relay, a' secondslow-acting relay under the control of said first mentioned slow-actingrelay anda ringing relay alwaysunderthe joint control of said scondslow-acting relayand a calling subscribers substation apparatus.

, 2. In a signaling system, the combination-of a line relay, aninterrupter for ca using said line relay to vibrate, a slow-acting relayhaving a circuit closedin the actuated position of said line relay, asecond slowacting relay'having a circuit closed in the actuated positionof said first-mentioned slow-acting relay, and a ringlng relay havingposltlon of 3. In a signaling system, the combinatlon of a calllngsubscrlbers line, a line relay controllable over said line, an impulsesend ing device, operated by the calling subscriber for controlling saidrelay, a slow-acting relay having a circuit including the frontconrelay.

having a circuit including the front contact of. said line relay, a'second slow-acting relay having a circuit including the front contact ofsaid first-mentioned slow-acting relay and the back ,ontact of said-linerelay, and a ringing elay having a circuit including the front I ntactsof said line relay and said secon slow-acting relay.

5. n a telephone signaling system, the combination with a telephoneline, of a line relay, an electromagnetically actuated inter: rupter'inone limb of thetelephone line, a manually operated switch in shunt ofsaid interrupter, a slow-acting relay under the control of said linerelay, a second slowracting relay under the control of saidfirst-mentioned slow-acting relay, and a ringing relay under the controlof said second slow-acting.

6. In a telephone signaling system, the

' combination with a telephone line, of a line .relay, anelectromagnetically actuated interrupter in one limb of tl1e telephoneline, a manually operated swltch in shunt of said interrupter, aslow-acting relay having a circuit closed in the actuated position ofsaid line relay, a second slow-acting relay having a circuit closed inthe actuated position of said first-mentioned slow-acting" relay, and aringing relay having a circuit closed in the actuated position of saidsecond slow-acting relay.

relay, an electromagnetically actuated interrupter in one limb of thetelephone line, a

manually operated switch in shunt of said interrupter, a slow-actingrelay having a c1rcuit including the front contact of said line CHARLESL. GOODRUM.

Witnesses: V

E. EDLER, K. L. STAHL.

7. In a telephone signaling system, the combination with a telephoneline, of a line

